While there are many welding practices used for joining workpieces of many metal compositions, there remains a need for a method of forming a sound, low resistance, welded joint with minimal deformation between two copper workpieces. There is a particular need for such a joining method for use in forming welded connections between separate pairs of copper conductor bars, in an assembly of many such copper conductor pairs, in a stator member of an electric traction motor for a vehicle. There is an additional need for a wire joining process that requires generation of minimal heat such that polymeric wire insulation near the joint is not degraded by thermal exposure.